c# Linq's - GroupedEnumerable usages?
.net-4.0, c#, ienumerable, linq
Solution
If you have an object in .Net, it has to be of some concrete type, it can't be an interface. So, for example, `new IList<int>()` is not valid, you have to do something like `new List<int>()`.
If you have a variable, its type can be an interface, so you can write, for example, `IList<int> list = new List<int>()`.
And that's exactly what's happening here. The type of the variable `grouped` is `IEnumerable<IGrouping<string,Fruit>>` (although it's not clear from the code, because you're using `var`). The type of the object referenced by that variable is `GroupedEnumerable<Fruit, string, Fruit>`, which is an internal type used by the implementation of `GroupBy()`. It can't be `IEnumerable`, because you can't have an instance of an interface.
The Visual Studio debugger is showing you the runtime type of the object, because that's what debugger is for: to show you the runtime information.
Problem
``` Fruit[] data = new[] { new Fruit {Name = "Gala",Type = "Apple",Price = 0.75m,Quantity = 10}, new Fruit {Name = "Granny Smith",Type = "Apple",Price = 0.80m,Quantity = 7}, new Fruit {Name = "Tasty",Type = "Strawberries",Price = 1.90m,Quantity = 20} }; var grouped = from fruit in data group fruit by fruit.Type; ``` `grouped` type is : `System.Linq.GroupedEnumerable<ConsoleApplication15.Fruit,string,ConsoleApplication15.Fruit>` have a look on it : my question : if grouped contains items ( implements ienumerable ) - why its type is `GroupedEnumerable` and not ``` IEnumerable <System.Linq.IGrouping<string,ConsoleApplication15.Fruit>> ``` why did they create a new Type aka `GroupedEnumerable` ?